Mysqltuner

FAQ

name resolution is active : a reverse name resolution is made for each new connection and can reduce performance

Option skip-name-resolve

 

Table cache hit rate: 0%

hmm

innodb_log_file_size should be (=16M) if possible, so InnoDB total log files size equals to 25% of buffer pool size

That's current situation, so change log_file_size together with innodb_buffer_pool_size

Attempted to use login credentials from Debian maintenance account, but they failed.

Find the secret mysqltuner config or use

mysqltuner --user root

or

mysqltuner --defaults-file ~/.my.cnf